Review - Focusrite AM2 Dante Headphone Amp

The smallest and cheapest of Focusrite’s premium RedNet range of Dante AoIP interfaces, the AM2 headphone amplifier was praised by me when it was announced as an example of a welcome trend towards small, low channel count endpoints which allow AoIP hardware to exploit one of its principal advantages: Distribution.

This trend towards smaller network nodes has continued and the number of units available which support a couple of inputs or outputs is quite high but many of these “endpoints” (network audio speak for a source or a destination for audio) are aimed at the installation market - a far bigger market than pro audio and one with a different set of priorities. For Dante products aimed at the professional recording sector Focusrite’s RedNet hardware is both highly visible and highly respected. So what does the AM2 bring to the party?

AM2 Hardware

Housed in a compact but beautifully constructed all metal box, this is a rugged, 2 channel headphone amp. The front panel presents a single, metal-nutted 1/4” headphone socket. The combination of metal nut onto aluminium casework means that this is sturdy and suitable for everyday use - Why some manufacturers still think plastic nuts or worse, un-nutted headphone sockets are acceptable is beyond me.

The top panel features chunky, solid aluminium pots for headphone and line out level control as well as LEDs for power, network status, signal present and line out local mute, the latter of which is toggled by a switch next to it.

The back panel features two XLR M line out sockets, two Neutrik etherCON RJ45 connectors and a 12vDC input for the supplied AC adaptor. On the subject of power, the most elegant way to use this unit is to power it via PoE (power over ethernet - think phantom power but for network cables). If you have a switch which supplies PoE then the DC power supply is unnecessary but it is useful to have as many network switches don’t support PoE. The back panel features two ethernet ports, the second can be used to daisy-chain devices.

Underneath it has rubber feet and a thread adaptor to accept a mic stand - perfect for busy sessions as this box is far too pretty to be trodden on.

Ultimo Module

The reason Dante devices are so compatible with each other is because they share standard network interface hardware. If a manufacturer wants to develop a Dante device they choose the appropriate Dante module from Audinate (the makers of Dante), and design around that. There are a few modules available but the two most common are the Brooklyn, which is commonly found in rackmount equipment and offers up to 64/64 IO and the Ultimo, which offers up to 4/4 IO. The AM2 uses an Ultimo module. Channel count decreases with increases in sampling frequency so at 96KHz the Ultimo can support 2/2 IO and as an output only device you can see that from a network point of view there are two unused input channels- though it should be said that talking about inputs and outputs can get confusing in AoIP and terms like “reciever” can be less ambiguous. Although outside the scope of this review, Dante carries a cost per channel and Audinate have released additional modules such as the 2 channel Analog Output module and the 16/16 Broadway module to allow manufacturers greater efficiency when deploying Audinate modules. In this case the Ultimo is the correct choice as 96KHz operation is important in a professional system and this is the only module to offer 2 channel output at 96KHz.

AM2 In Operation

This is a simple box and setting it up and using it presents no issues. Audio performance is exemplary. It drives headphones cleanly to levels I don’t want to be around for too long. Plenty for a drummer who wants his eardrums to meet in the middle (don’t try this…) and the line outputs offer analogue attenuation for active monitors. I’m yet to try any Dante monitors but a glaring issue with implementing them is that Dante controller doesn’t offer level control and I’m very wary of any software-only control of speakers or headphones. We’ve all had software crashes spit full-scale noise into our ears and I feel much safer with an analogue control between me and the noise! In Dante Controller the AM2 shows up as a 2 channel receiver, so the headphone and line outputs carry the same mix.

The large aluminium knobs allow fine level adjustment, often difficult with small diameter knobs. My only gripe with the construction was that these knobs, when tightened up onto the pot shaft via the grub screw, sit slightly off-centre giving them a tiny, eccentric “waggle” when they rotate. A small detail but one which I noticed and then couldn’t un-notice.

As the lowest cost entry point into the RedNet range, and because of the inherent cross-compatibility of Dante, the AM2 is a very worthwhile purchase for anyone wanting to get into the Dante ecosystem. As a high quality, output only audio interface I found I used it quite a lot on its own with a MacBook Pro and a pair of headphones, Comparing the quality of the headphone outputs on a Red4Pre to the AM2 I found them equally capable. While a little over £300 might seem expensive for a headphone amp, the modular nature of Dante means that this box will always be useful while you are using a Dante system and as it is a high quality box, an AM2 which is powering some headphones next to your laptop today could be controlling your local playback monitors in the live room of a RedNet based studio in the future.